Schmallenberg virus (SBV) causes congenital malformations and stillbirths in cattle, sheep, goats, bison and possibly camelids. Wageningen Bioveterinary Research conducts research on this disease.
The virus was first characterised in 2011 in Germany from samples from diseased dairy cattle. The virus was named after Schmallenberg, in North Rhine-Westphalia, Germany, from where the first definitive sample was derived. Later on, after Germany, the virus was detected throughout Europe and surrounding countries.
Negligible risk for humans
Based on the current available information, experts concluded that the risk for human health is negligible.
The viraemic period of Schmallenberg virus is short and the virus is transmitted by biting midges, with apparent similarity to the vector transmission of bluetongue virus.
The risk of disease spread from trade in meat and milk is negligible. For semen, embryos and live animals research institutes have made recommendations for safe trade.
Diagnosis of Schmallenberg
Experimental infection in cattle and sheep showed no clinical signs or mild symptoms at 3 to 5 days post-inoculation with an incubation period of between 1 and 4 days and viraemia lasting for 1 to 5 days.
Since early December 2011, congenital malformations have been reported in newborn lambs in countries in Northwest Europe, and SBV was detected in and isolated from the brain tissue. Stillbirth and congenital malformations with PCR positive results have also been reported now throughout Europe and surrounding countries.
Manifestation of clinical signs varies by species: bovine adults have shown a mild form of acute disease during the vector season, congenital malformations have affected more species of ruminants, in particular sheep and goat. From some sheep and cow farms diarrhea was also reported.
Schmallenberg virus epidemic in the Netherlands: spatiotemporal introduction in 2011 and seroprevalence in ruminants
Schmallenberg virus detected by RT-PCR in Culicoides biting midges captured during the 2011 epidemic in the Netherlands
Schmallenberg virus detected in Culicoides biting midges in the Netherlands in 2011In: Proceedings 16th International Symposium of the world Association of Veterinary Laboratory Diagnosticians, 5-8 June 2013, Berlin, Germay. - - p. 84 - 84.
Schmallenberg virus detected in Culicoides biting midges in the Netherlands in 2011In: Proceedings International meeting on Emerging Diseases and Survreillance, Vienna, Austria, 15-18 February, 2013. - - p. 176 - 176.
Development and validation of an indirect Enzyme-linked Immunosorbent Assay for the detection of antibodies against Schmallenberg virus in blood samples from ruminantsResearch in Veterinary Science 95 (2013)2. - ISSN 0034-5288 - p. 731 - 735.
Schmallenberg virus epidemic in the Netherlands: Spatiotemporal introduction in 2011 and seroprevalence in ruminantsPreventive Veterinary Medicine 112 (2013)1-2. - ISSN 0167-5877 - p. 35 - 47.
Genetic characterization of an atypical Schmallenberg virus isolated from the brain of a malformed lambVirus Genes 47 (2013)3. - ISSN 0920-8569 - p. 505 - 514.
Schmallenberg virus outbreak in the Netherlands: Routine diagnostics and test resultsVeterinary Microbiology 165 (2013)1-2. - ISSN 0378-1135 - p. 102 - 108.
'Schmallenberg virus' - a novel orthobunyavirus emerging in EuropeEpidemiology and Infection 141 (2013)1. - ISSN 0950-2688 - p. 1 - 8.
Schmallenberg virus in Culicoides spp. biting midges, the Netherlands, 2011Emerging Infectious Diseases 19 (2013)1. - ISSN 1080-6040 - p. 106 - 109.